In about 95% of airspace above the continental United States below 10,000 feet, there is no current or planned Federal Aviation Agency requirement for aircraft to broadcast their location. Manned aircraft, and unmanned aircraft systems (UASs) such as unmanned aerial vehicles (UAVs) should be able to avoid other piloted and unmanned aircraft that may not be broadcasting their location. Routine access of the UASs to the National Air Space (NAS) of the United States is expected to require a means for avoiding collision with the other piloted and unmanned aircraft.